Conventional power shredder typically comprises a shredding mechanism cover head and a waste collector. The shredding mechanism cover head usually attaches to the top open of the waste collector. Typically, shredding mechanism cover head includes a motor, a gear assembly and a rotary cutter apparatus. Because of the one unit design of the conventional power shredder any defects in the shredding mechanism cover head parts, the user generally have to send the entire shredder back to the shop for repair. The wait time for repairing might take some time and for the user it is troublesome to have to wait for the shredder to be repair at the mean time.
Furthermore, for the shredder manufacturers, retailer or the service department the process to repair a shredder might also prove to be troublesome. Different model of shredders might have different configuration and use different model of parts. Therefore, repairing a shredder some time may take a relatively high cost and time for the manufacturers, retailer or the service department.